The present invention is directed to bicycle computers and shift control devices for bicycle transmissions and, more particularly, to a modular and distributed computer assembly that may be added to an existing shift control device and that allows the rider to view the computer display, operate the computer control mechanism and operate the shift control device conveniently.
Bicycles sometimes are equipped with computers that measure and display various riding parameters such as speed, cadence, distance traveled, etc. The operation of the computer and the information displayed is usually controlled by buttons on the computer. Because the rider must carefully view the road in front of the bicycle while riding, it is usually desirable to place the computer in the middle of the bicycle handlebar to minimize distraction when viewing the computer display. However, if the rider needs to change the operation of the computer or the information on the computer display, the rider must remove his or her hand from the bicycle's brake and/or shift operating device to operate the control buttons on the computer. That is usually undesirable during a race where such hand removal can slow the rider considerably.
The disadvantage of removing the rider's hand from the brake and/or shift operating device can be minimized by placing the computer next to the brake and/or shift operating device. However, then the computer display is located far from the center of the bicycle, thus requiring the rider to look to the left or right in order to check the computer display. High performance riders find such a distraction unacceptable.
Some bicycle computers have the ability to control a bicycle shifting device such as a motor controlled derailleur or hub transmission or at least display the sprocket or gear ratio currently selected by the shift control device. Such computers usually have sensors installed to the shift control device for detecting the position of the shift control device, and the position of the shift control device is used to calculate the currently selected sprocket or gear ratio. As a result, the computer and shift control device are usually constructed and sold as a unit. Of course, some riders may not want or need a bicycle computer, so a different shift control device must be constructed without a computer, even if the remaining parts of the shift control device are identical to the shift control device sold as a unit with the computer. This increases manufacturing and inventory costs. Also, if a rider who buys a shift control device without a computer later decides to add a computer to the bicycle, then the rider must buy the shift control device sold as a unit with the computer because there is no way to install the sensors to the originally purchased shift control device. Thus, there is no flexibility to upgrade.